Indicator and stop for magnetic wire recorders



H. NYGAARD INDICATOR AND STOP FOR MAGNETIC WIRE RECORDERS Sept. 23, 1952 2 SHEETS.SHEET *1 Filed Aug. 25, 1945 A #ERMAN zvymuko BY I M,M,?flnm%@mw 4r 15 if 15 ATTORNEYS INDICATOR AND STOP FOR MAGNETIC WIRE RECORDERS Filed Aug. 25, 1946 H. NYGA ARD Sept. 23, 1952 2 SHEETS-SHEET 2 INVENTOR -r- HERMAN IVYJAARD ATTORNEYS Patented Sept. 23, 11952 INDICATQR AND-STOP FOR MAGNETIC,

WIRERECORDEBS Herman Nygaar'd', Poug likecps'ie,*'N. Y. .ApplicationAugust 2 1946,.Seria1-No. 692- 724 1 This invention relates to a position indicating and;- stop actuating mechanism operatively asso:

ciated witha continuously advancedwir-e .or likefilamentary member. Mechanism in accordance with the invention may advantageously-be incorporated sound recording and reproducing ape paratus employing a wire of magnetic material as around medium, although, as will be apparent, the invention is not limited to such application.

In magnetic wirerecorders of conventional deesign-a fine wire having suitable magnetic properties is advanced past recording or reproducing pole pieces while unwinding from a supplyspool and wi d ng on e-up' r'tempomry -s-te ae spool. -lQo-providea long playingrecord the-twire may be. several thousand .feet in length andtherefore it becomes highly desirable to have a reliable indication of s theposition along 1 its length at which the recording or reprodueingimeanszis set to operate; both to =keeprtracl; of the relation between the usediandr unused .lengthsofr the .wire and to be able to index and subsequently iden tify difierentportions-ot a .record.

-In :recordersoi earlier design such-indication 1 has commonly :been. furnished by a scale and 25 pointer arrangement wherein. one of the amenibers was-positively driven, .a-s fey-gearing, from the shaft mounting one-of-the wire spools, the

other member bein stationa ry. With such can arrangement the: indicationf-urnished :--is reliable only if 415116 'wireend indicator have first been synchronized -in a. reference position, .forexam-- ple, at .anend. of the wire with one spool empty and the otherinll. :If thiscannot-be done or. if the relationhetween wire. and indications-changed after .the indicator has been set, ,aswhen partiallywound-spools are mountedson the-a paratus,--the indication may be .false. Likewise, when a. stop is provided for the purpose f in activating the wire-driving. means when the endof the wire is reached-and .this stopscomes into play .ataposition determined by the aloove indicator .means,, or. mechanism .actingin synchroe nism .therewith, the stop cannot, :in general, be

reliedupon to perform its function in connection with spools mounted in a partly wound condi tion.

".The.presentinventionovercomes the above and other .disadvantagesoi theprior artby providing indicator means whose operation is not based upon the measurement of the number of revolutionspfromta reference position, .made b v.one of-lthe spoolsbutlinstead is basedupon the ratio oflthetrotational.. speeds. ofethe .twospools. This speed. ratio isldetermined by .the .diametersof the.

turns oi '1 the windings -on 'fthel respective (spools v Claims,- (Cl. 242-54 between which the wire s transferred, and: vari s inversely with the...relatiQX b1 WBBn...aid .diangfir ters, due .to thev necessarily .uniformilmear V6 90..- ity ,of an .rzortionsoi the w e under oi g it. n;- feral. [When the wireis. .of considerab e 1 h it i -as on the spools in. multipleflayersam the diameter of the turnsin, the nte more:

ach. windms sarunctionof the...1ensth.oi w re onthe spool whicnundercertain conditionanmg approach direct proportiona ty alth u 1, 1.? el ti sh p-is notv necessary .t rthe .en rationot e. inventionilt. follows, then, that the lratig oi the. rotational speeds of .thel-spoolslin suchan arrangement is, at any time, a measure of the ratio of .th lengths, of wire respectively carried thereby,

,The I invention, 1 hy.- utilizing .thi$ p ilil iple, -DXLO:

vides indicator means in the operation ofwhich,

once an initial adiustmenthasbeenmade inaco danc with the tyne sin-spool and standard length of wire used, the indication oi-therelatiye lengths of vwire on thetwosponlsbecomes inde pendent of the amounts of wire in the wi din s when the, spools aremountedinthe appa atti The invention also .comprises ,a :stop. operated y t .i icatoraactuatins. eans and .e i ny independ nt of, the. initial-relationb tweenthe amounts of Wire on the two spools.

It. isan. object of the invention tarrovide. .1 apparatus em loyin a .Lnlamentary member or selectedllength'transferable ,loetween levehwound multip-le layer windings thereof .91 .,a ,,nai1i 9i pools of selected d me sions, sup lyin during operation a continuous indication ofithe relative lengths of wire n thesnoqls which inde endent of the. i.

ia r lation therebetween when the spools. arelintroldllqed into. theat es:

ratus.

Another object" is torwvi'dein apparat th a ve character. in ansmr yiding ilthe rela ire' n ths ofit e mem cordancewith therelation.hetweentherotationel speeds, of thelsnoojls, as controlled by. the e tion between. the diamete s-9f the urns of here tive outer' layers. of.,said multip le,-1a

thereon.

Another obiectis t9 Provident.apnaratusnfitlie aboyacharacter ,seli-adiusting means. continuous ly repositione .dur nepperation. accordance with the; varying. speed. ratiosof 1 thesnwls as the filamentarymemberjis transferredj'betwfionf layers. or. the multiple-layer windinesresp carried gthereby iorljindicatingaand. .coiitrolupui poses. i

., Another .ob'ject. is .iiO..;PmYide.. 1n .apnarati sepi if ember on the spools. whi i zactnat d in.

the above character having means for driving one of the spools thereof, an adjustable stop for inactivating said driving means at a selected position of the filamentary member.

A further object is to provide apparatus of the above character which is especially adapted for use in connection with sound recording apparatus employing a magnetic record wire as the transferable filamentary member.

Other objects not specifically referred to will be apparent upon consideration of the means and method of the invention, as described herein.

According to its general aspects the invention contemplates the association with supply and take-up spools between which a wire or other filamentary member is transferable by rotation of the take-up spool, of a two-part speed comparison device having the parts thereof independently rotated through driving connections to the two spools, respectively. A difference in speed between the two rotating members of said device results in the repositioning of a speedadjusting member of an adjustable speed gear in'one of said driving connections, to wipe out the difference. The position of the speed-adjusting member provides a measure of the ratio of the speeds of the two spools and, hence, with level'winding of the wire in multiple layers, for which provision is made, measures of relative lengths of wire on the spools. At a selected position of the same member means are brought into play actuating a stop to remove power from the driven spool. V

The invention will be better understood from consideration of the following detailed description, with reference to the appended drawings in which:

'Fig. 1 is a plan view of indicator and stop means for a magnetic wire recorder, in accordance with the invention;

Fig. 2 is an elevational view of the mechanism of Fig. 1; I

Fig. 3 is a section along the line 3-3 of Fig. 2;

Fig. 4 is a fractional elevational view, as in Fig. 2, illustrating the operation of the stop mechanism at one limit of the travel of the record wire;

Fig. 5 is a fractional elevational view similar to Fig. 4.- illustrating the operation of the stop mechanism at the other limit of the travel of the record wire;

Fig. 6 is a partial section along the line 6- of Fig. 1.

In'the figures, which illustrate the application of the invention to a magnetic Wire recorder. thereis shown a shaft H, suitably journaled on the frame I2 of the apparatus, mounting takeup spool l3 on which, during the making and playing back of a record, magnetic record wire l5'winds while unwinding from supply spool I! mounted on shaft [9, also suitably journaled on frame 12, the shafts being in spaced parallel relation. The two spools are preferably, but not necessarily, similar in form and are illustrated as having rectangular winding spaces, which is a convenient but not necessary shape. To simplify the illustration of the invention the spools are shown mounted on their respective shafts intermediate other members carried thereby. In practice, the spools may be mounted at the ends of the shafts, to facilitate their insertion in the apparatus and removal therefrom. It is to be understood, also, that in its travel from one spool to the other wire 15 passes by recording, playback or'other means connected with the making V 31 fixed on and rotatable with a shaft 38, by

., spool H, by the pull of or through tension in the wire. Due to the requirement of uniform linear velocity in all portions the wire in the process of '4 and reproducing of the record. Such means form no part of the present invention and are omitted from the drawings, again in the interest of simplification.

For rotating take-up spool 13 in the direction indicated by the arrow to advance wire IS in what will be. termed the fiorward direction, which is the direction in which the wire advances while recording and playing-back of the record take place, and, alternatively, for rotating supply spool H in a direction which reverses the direction of advancement of the wire for rewind purposes, there is provided a reversing friction drive 20 actuated by a motor 2|. Motor 2|, through a reduction gear 23, drives a countershaft 25 on which are mounted conical friction disks 27 and 29. adapted to engage and rotate mating friction disks 3! and 33 on shafts H and I9, respectively. Selective engagement of disks 2'! and 31 or disks 29 and 33 is provided for by a splined coupling 35 between shaft 25 and the motor output shaft, together'with a shifter fork means of which the countershaft assembly may be displaced from the neutral position illustrated in Fig. 2 in either direction to eifect engagement of the desired pair of dislm. Preferably a higher speed during rewinding is provided for than during advancement of the record wire in theforward direction, this being accomplished by suitable ratios of the diameters of the two pairs of disks.-

In accordance with the principles of the invention, the record wire I 5 is wound on spools l3 and I! in multiple layers. In other applications of the invention employing a relatively large size wire or other filamentary member, a perfectly uniform distribution in even layers may be achieved, but in theillustrated case of a magnetic recorder the fine size of wire used, of the order of 0.004 inch in diameter, makes it impractical to may be had by the use of means for traversing the wire at a suitable rate to and fro across the winding space of the spool on which it winds,-

thereby approaching an even layer distribution. A distribution such as is attained by these means is termed herein a level" winding. To this end an arrangement is provided, best seen in Fig. 3, in which shaft H, by way of meshing helical gears 39, 4!, the latter on transverse shaft 43,

drives a heart-shaped cam 45 on shaft 43. Cam

45-has a bent, rocking follower 41, pivoted at 49, provided with an elongated slot 5| in" the end of the arm thereof remote from the cam and having;

the end of the other arm thereof pressed against the cam periphery by a spring 53. Slotilserves as a guide for the record wire and due to the traverse of this guide, by means of cam 45, across the winding spaces of spools l3 and H, at a greatly reduced rate relative to the rotation of the spools, the wire when winding on either spool is arranged as a level winding. In certain arrangements,

particularly when the winding spaces on the spools are relativelynarrow, the described wire traversing means may be dispersed with, the wire automatically. winding in substantially a level manner.

Rotation of one of the wire spools, for example spool l3, rotates the other spool, for example transrerai from one spool; to: the other, the reiae tion hetweentheiangular velocities'or rotational speedsiof the lspoolszva'ries. inversely as the ratio of the-diameters of. the outer layers of. the respective'windings thereon changes. According to the invention-a. comparison ismade betweensaid ro tatio'nal speeds To this end a two-part speed comparison device is provi'ded" comprising acro tatable shaft 55 which is also slidable axially in.

itsbearings 56 56", and:..one oI- gearsi 51,591 ref-'- strainedl'y rotatable ther'eab'out; Gear 51 is ac-- tive andrgear 5'9: inactive duringi iorwa'rd. ad-

vaneement or. the record wire while during rewinding theoppositeis true; as will be explained. Shaft 5 is rotated fro-inshaft It, mounting spook-ruby g Wayhi' 'worm til wormw-h'eei stand aamstamespeeu gear '-'65 ,.compnsing frictionc'one: 61 and 'iriction whee1 69 fixedion shaft 55. Gear li-l or 'ge'ar 59 the sele'etion-beingmaue by meansl'atterfight-hand, and the two gears are "respectively engages with these' -grcuwesor threads'by suitable means, illustrated in Fig. 6 'in'conne'ct'ion with gear 59 as 'a'pin 1-1 which may have a pressed fit in-thehub of the gear anda loose fit inright hand g'roove I5. 's imilar'means'"'(not shown) are provided for engaging? gear roove 13. l v I Gears 5! and 59, 'spacedby a collar 19; are held between the two armser' a yer-ea: each h'aving a hole through which shaft '55 passes loosely. rose a I' has area-extension s 3- threaded at the end to receivenuts B S- andal, serving as adjust ab l'e' abutments for a l'eaf spring -83 fitting over the rod, together with respective lock nuts ana at. 7 Spring '89 retest to shaft 38 ata notched portion 9| thereof 'fordisplacement with the shaft. Shaft 38 bearing spring 89 and shift er'for'k 3"! is selectively rotatableto three posit i'ons by the angular displacement of a control 51 with left-hand knob 93 fast on a shaft 95- which mounts a cam;

91 havinga followers!) pivoted to stationary means at IBI and pivotallyconnec'tedatthe end thereof, opposite the cam to a pairo'f longitudina'lly displaceable latch arms I03 and I35. 'A

spring ["03 holds the'follower against-the perip-hr eryof the cam. Spread and bent end portions fill and IilSl of' arms Hi3 and I55,'respectively, are urged toward engagement with opposite longitudinal ejdges of a bail III by aspri'ng ll3'connecting the'two arms'. See Fig; '6. Ball III is mounted for rotation about shaft 's'sand f r; translation therewith, the latter motion being provided for by a shouldered end portion I I5 of shaft 55 allowing slight axial clearance, and a retai'ner screw II1.

Latch arm. I03 has a not'h'ed inner edge including a portion I I3 extending normally of the longitudinal axis of the arm whilearm I05 has a notched inner edge of different contour including a portion I21 also extendingnormally of-the axis of the arm. In the position of the armsv shown in Fig. 2 longitudinally extending portions of the respective notched inneredg'es of the latch arms are pressed by spring H3 against one pair of opposed faces of a square boss I23 while normally or transversely ext'endingportions H9 and I2I of said edges are in loose engagement wlththe pair of opposed faces of boss I23 at right angles to saidfirst pair. v Boss I23 extends from anarm I25 fixed to shaft 38. V

It will be apparent that-longitudinal displacesmerit of: latch arms I33, H15, in eitlzier:dii eciifonq,, by the operation. of. knob 93 and displacement or. cam 91 andrfollower' 99;, is effective to: cause cor-re? spending: angular displacement of shaft 38- In" one. direction of. displacement of the latch arms; motionis transmitted by'theiengagementlof notch edge H9 or arm 103 with boss I23 and in the.-

other direction by the engagement. of: notch edge; I2I of arm I05with-theb'oss;

The three: positions of. kn'ob' 93 are designated on. a station'arymarking plate I21 asr-"Forward';.'" Neutral and -"Rewind,respectively. 'Wi-th" the knob in the Neutral position cQndilliOllSMllLbflS? shown iniiFig'. 2 iftthe knob hasbeeniturned'thereto from the: Forward position. Latch arms I53,

I05 are: at the mid 'position or theirutravelp Shifter fork 31 is positioned? to uisen agetotn,

pairs vof drivingfriction disks2-l, 3| and- 22, Leaf'spring 89 exerts no pressurete'ndi-ng to more rod 83 and yoke 8i attached thereto. Gear 5 therefore remains engaged with worm I I as it was whenkn'ob 93'wasin theForward position.

If; now, knob 93 is againturned to-the Forwardpositionlatch arms I03, I05 'aredis'placed towardthe right thereby causing -notch edge I21 of'arm- I05 to carry-boss I23 to the right and angular-ly displace arm I25and shaft? 38in a counteractswise direction. Shaft 38 carries with iii-shifter fork 31 to cause engagement "of friction disks 21',

3| andth'e driving'ofspool I3. Angulardisplacement of shaft 38 also displacesl'eaf'spring -89 which meets abutment nut 3'! and is resiliently deformed, therebyfholding 'gear fil {in engagement WithWOll'll TI. seen in Fig. 4.

If instead, knob Q3 isturned from the Neutral" position illustrated in Fig. 2 to the Rewind 'posi tion, latch arms I03, I35 are shifted toward the} left, with notch edge I I9 actively engaging'boss I23 to rotate arm I25 and shaft 38 in a clo'ckwise direction,, thereby displacing fork 31- 'to the right and causing. engagement of friction disks.

29, 33 and the driving of spool Il Spring 89 isalso rotated in a clockwise direction and meets abutment nut 85, thus displacing rod 83 and yoke 8| towardthe left. The travel 'of'yoke' BI is sufficient to disengage gear 51 from worm 1 I and engage gear 59 therewith, under urging. of spring 89'.

If knob 93 is 'again'rotated to the Neutral post tion the motor drive is disconnected but gear 59 remains in engagement with worm -II'.

The position indicating functionof the means of theinVention may now beex'plained; Assume, first, that knob 93 is in the: Forwardpositio'nz Rotation of spool I3 transfers wire thereto from spool I! and the traversing of the slotted arm oi" cam follower 41; with which thewire-is' engaged; across the winding space of the. spool arrangesthe wire in a multiple-layer level winding there brakes I29 and I30 may anti-respectively, on the-- hubs of spools I3 and I1.

Should the speed ratios between shaft II and" shaft and between shaft I9 and gee-r51 re- This condition of the spring is the resilient however, gear 51 rotates at a higher speed than shaft 55 the engagement of the gear hub with left-hand groove I3 in the shaft causes the shaft to be displaced toward the left in its bearings,

the gear being held against axial displacement: Shaft 55 carries with it friction,

by yoke 8|. wheel 69 of adjustable speed gear 65 and thereby increases the speed ratio of this device to speed up shaft 55 until it rotates at the same speed as gear 51. In a similar manner if gear 51 rotates at a slower speed than shaft 55 the shaft and wheel 59 are displaced toward the right until equality of speed between the shaft and gear is established.

In its axial travel shaft 55 also carries with it.

bail II I which has a laterally extending arm I3I rotatably mounting at its outer end a roller I33 positioned between a pair of guide members l35, I35 attached in an oblique position to a longitudinally displaceable bar I31 slidable in brackets Roller I33 is held centralized in the oblique guide formed by members I35, I35 through thecentralizing action of spring I I3 and latch arms I03, I05 onbailIIl. f

zAssume, now, that at the start of operation substantially all of record wire I5 is on supply spool I! and that index I03 is adjusted, with the spools rotating, to the marking designated 100 on scale I4I, to indicate that 100 per cent of the wire available for record purposes is unused. The turns of wire in the outer layer of the winding on spool I? are of relatively large diameter while the corresponding turns on spool I3 are of relatively small diameter, assuming similar spools. Spool I3 therefore rotates faster than spool I1 and the ratios between the speeds of shaft II and shaft 55, and shaft I7 and gear 3, respectively, are so chosen that under this condition when shaft 55 and gear 51 rotate at the same speed, wheel 69 is near the right-hand limit of its travel, to attain a maximum speed ratio in in the outer layers of the windings thereon change in complementary manner, the winding on spool I3 increasing in diameter and the winding on spool I1 decreasing in diameter. As this occurs shaft 55, with wheel 59, moves toward the left due to the balancing action of the speed comparison means comprising this shaft and gear 51, as has been described, and scale I II moves relative to index I43 to provide a continuous indication of the percentage or the length of the unused portion of the record wire I5.

Any suitable units may be used in graduating scale MI and, if desired, two sets of graduations may be provided, reading in opposite directions, for the direct indication of the lengths of both the used and unused portions of the wire.

Advancement of the wire in the forward direction may be stopped at any time by operating knob 93 to-the Neutral position and the wire may then be rewound on the supply spool by operating knob 93 to the Rewind position, with the shifting of the drive to spool I'I; During the re--" winding operation the movement of scale I relative to index I43 is the reverseof that described above. The movement inthis case is controlled by a comparison of the speed of gear 59 with that-of shaft 55, gear 53 being engaged with worm lI underthis condition instead of gear5l. When gear 59 is driven from shaft I9 at a faster rate than shaft 55 is'driven from shaft II, the engagement of the gear hub with right-hand groove 13 in the shaft, by way of pin '11 causes the shaft to-shift to the right and carry scale I with it, to rebalance the two speeds, thisbei a the normal action which goes on during the rewinding operation. The gear, as pointedout in connection with gear 51, is axially restrained by yoke-8I thereby serving as an axially stationary nut for the grooved shaft. Should gear ,59 run slower than shaft 55, for some reason, the speed balancing operation shifts shaft 55 andconnected.

members to the left. a

The graduation of scale MI is not a linear one' throughout the entire range, and is best determined experimentally. The law of variation of the relative displacement of scale MI and index I i-3 with transferal of the wire from one spool to another is dependent, among other factors, on the ratio of width to depth of the winding spaces of the spools. If true layer winding were achieved, progressive changes of indication along scale MI theoretically would take place only as changes from one layer to the next occur in the windings,

the changes between successive layers, :in gcneral, not occurring simultaneously-- in the two windings. With narrow winding spaces these progressive changes of indication would occur more frequently than with wider spaces. In practice a true layer winding is not achieved and the change of indication becomes substantially continuous, or at least the discontinuities are of a lower orderof magnitude, on the basis of percentage of the total scale length, than possible:

irregularities in indication due to other causes. Aside from the above considerations the effect of narrow winding spaces on the spools is to give relatively large rates of change of indication at the beginning and end of the winding and rewinding operations, while wider winding spaces result in a uniform rate of change of indication over a. greater portion of the scale, with a less sensitive indication at the ends thereof. For most uses the latter type of indication is to be preferred.

In order to stop the wire drive when all of the wire has been wound on either spool, left-hand and right-hand stationary stops I5I and I53, respectively, are provided at suitable locations. adapted to engage bar I37 at the limits of its travel and deactivate the wire drive. The positions of these stops may be adjustable. Their operation at the end of the forward advancement ofthe wire and the end of the rewind operation is illustrated in Figs. 4 and 5, respectively.

Referring first to Fig. 4, bar I31 having been stopped in its travel by coming against stop I53, any further shifttoward the right of bail III carrying roller l33 causes the roller to be displaced downwardly, as seen in the figure, through the action of guide member I35. This displacement of the roller rotates bail I II about the axis of shaft 55 (Fig. 1) against the force of spring [I3 and thereby displaces latch arm I05 downwardly,

spring 89. When latch arm I05 moves down- *tiono'f bail l l l has caused roller wardly until the upper extremity of notch edge l'2l clears boss" 123 on arm I25, the restraint on :sha'ft 38 isremoved, since bossl 23 can now move to the leitand theshait springs back to a central-position thereby moving-shifter fork 31 (Fig. '2:)**and operating":countershaftZfi to its central .position in which the friction disks of the wire drive 20 are disengaged. Advancement of wire IS issthusstOpped. Latch arms I03, I are not displaced longitudinally in the tripping operation above described but in moving knob 93 to the Rewind position the Neutral position is passed "through, in which the latcharms are centralized.

Referring, now, to Fig. 5, the condition illustratedis: the trippi'ng'of the latch holding the ifriotion :drive disks engaged when the end of the ,rewinding operation is reached. 'B'ar I31 has moved to the left to engagement with stop 1'51 andsa further movement in the same direc- [33 to be displaced upwardly through the action of guide I 35, thereby rotating" the ball against the force spring I I3 in a direction which has moved iatch arm Hi3 upwardlyuntil notch edge H9 of. friction drive 20 and stop advancement of the wire in the 'rewind direction. The. means and method of operation of the invention disclosed herein provide for the continuous indication oillthe condition of a filamentarymember, as to the relation of the lengths oftheflmember on the two spools, during the reversible transferal thereof between a pair of spools on which the member winds. stoppingof the advancement of the. member when traveling in. either direction between the spools is also provided for. I

It is to. be understood that the embodiment of theinvention described herein is by way of illustration, 0111;Y 3;I1d. not byway ;oflimitation, the scopeof the invention being defined solely by the appended claims.

lclaim:

1. In combination a pair of spools respectively rotatable about spaced axes, a filamentary member extending, therehetween. for winding in multiple layers thereupon, motive means for directly rotating one of said spools and thereby through tension in said member rotating the other .spool to effect transfer of the member between the spools, and meansfor continuously indicating the relation between the rotative speeds of said spools comprising a pair of individually rotatable speed comparison members,

driving connections between said spools and said members respectively, one of said connections including an adjustable speed gear, means for automatically equalizing the rotative speeds of said comparison members by adjustment of the speed ratio of said gear, and indicator means controlled in accordance with said adjustment, said adjustment being proportional to the ratio of the diameters of the outer layers of the windings on the two spools and thereby a function of the ratio of the lengths of the filamentary member constituting said windings, respectively.

2. In combination a pair of spools respectively rotatable about spaced axes, a filamentary mem- Automatic berextending therebetween for winding in multiplelayers thereupon, motive meansfor directly rotating onenof. said spools and thereby through tension in said member rotating the other spool to effect transfer "of the member between the spools, traversing means in engagement with said member operative to produce level windings thereof on said spools, and. means for continuously indicating the: relation. between the rotative-speedscf said spools comprising a pair of individually rotatable speed comparision members, drivingconnections between said spools and said membersrespectively, one of saidconnections including an adjustable speed gear, means for automatically equalizing the 'rotati've speeds of said comparisi'onmembers by adjustment. .of the speed ratio o'f said gear, and indicatorwmeans controlled in accordance with said adjustment, said adjustment being a function of the ratio of the lengths of the filamentary member constituting said windings, respectively.

3. In combination a'pair of spools respectively rotatable about spaced axes, a filamentary member extending thereb'etweenfifor winding in multiple layers thereupon, motive means fordirectly rotating one of*said'spools and thereby through tension in said member rotating. the other spool to eifect'tran'sfer of the member between the spools, .a pair of individually rotatable speed'comparison members, driving .connections between said spools and said members respectively, one of said connections including an adjustable speedgear, means for-automatically equalizing therotativespeeds of said com parison members by adjustment of the speed ratio of said gear, displaceable "means positioned in accordance with said adjustment, means for indicating the position of said displaceable means, and meansfor controlling said motive means upon displacement of said displaceable means to a preselected position thereof.

4. In combination a pair of spools respectively rotatable about spaced axes, a filamentary member extending therebetween for winding in multiple layers thereupon, motive means for di- 'rectly' rotating one'of said spools and thereby through tension-in said member rotating the other spool to effect transferof the member betweenlthe'. spools, traversing means operative to produceilevel wi'nilin1gs of said member on said spools, a,. pair of individually rotatable speed comparison members, ffl ne i ns. b tween;sa d;spools and said members respectively, one of" said. '0, nections including ,an adjustable speed..gearfl, for automatically equalizing the rotaltive speeds-of said comparison members by adjustment of the speed ratio of. said gear, displaceable means positioned in accordance with said adjustment, 'meansfor indicating theposit'ion .of said .di'splac'eab'le ,means. .as v.a. measure of the ratio of the lengths of the filamentary member wound on said spools, respectively, and means for controlling said motive means upon displacement of said displa'oeable means to a preselected position thereof.

5. In apparatus comprising a pair of spools rotatable about spaced axes and a filamentary member transferable therebetween upon rotatably driving one of the spools, said member forming multiple layer windings on the spools, means for directly driving one of said spools, said other spool being driven by the pull of the filamentary one of said spools; a nut on said shaft, connections for rotatably driving said nut from said other spool, an adjustable speed gear in one of said connectons having a continuously displaceable speed adjusting member, said adjusting member being operatively connected for displacement responsive to relative axial motion between said shaft and nut resulting from inequality of the respective speeds thereoef in a manner to reprogress of a filamentary member transferable between a pair of rotatable spools on which the member winds in multiple layer substantially level windings, motive means for directly rotating one of said spools and thereby through tension in said member'rotating the other, the ratio of the rotative speeds of said spools being inversely proportional to the ratio of the diameters of the respective turns thereon between which the member is transferred, means for measuring and indicating said speed ratio and means actuated by said last means for controlling said motive means.

7. In means for controlling the progress of a filamentary member transferable between a pair of rotatable spools on which the member winds in multiple layer substantially level windings, motive means for directly rotating one of said spools and thereby through tension in said member rotating the other, the ratio of the rotative speeds of said'spools being inversely proportional to the ratio of the diameters of the respective turns thereon between which the member is transferred, means for measuring said ratio, a latch positionable to hold saidmotive means activated and means actuated by said measuring means for tripping said latch and deactivating said motive means at a pre-selected value of said speed ratio.

8. In means for reversibly transferring wire or like filament between windings on a pair of spools, a reversing drive for reversibly advancing the wire by actuation of one of the spools, a shaft having right hand and left hand threads, a pair of nuts respectively engaged with said threads, connections for driving said shaft from one of said spools and driving one of said nuts from said other spool, including an adjustable speed gear in one of said connections having a continuously displaceable speed determining member, said member being repositioned responsive to inequality between the speeds of said shaft and said driven nut, control means for concurrently selecting the direction of advancement of the wire by actuation of said reversing drive and selecting the driven one of said two nuts whereby the displacement of said member for like speed. differences may be reversed with reversal of the wire drive and said displacement caused to maintain equality between the speeds of shaft and'nut during advancement of the wire in either direction, and means actuated in accordance with the position of said member.

9. Means for controlling the transfer of wire or a like filamentary member in either direction between multiple layer windings on a pair of spools comprising a reversing drive adapted reversibly to advance the wire by actuating one of the spools, a threaded shaft, connections for rotating said shaft from one of said spools including an adjustable speed gear, a nut on said shaft, connections for rotating said nut from the other of said spools, means for readjusting said adjustable speed gear responsive to inequality between the speeds of said shaft and nut in a manner to restore equality therebetween, a control for said reversing drive settable to advance the wire in either direction including a latch for holding said drive in an operative condition, and means for tripping said latch responsive to a pro-selected adjustment of said adjustable speed gear.

10. In a magnetic wire recorder a pair of spools of similar form rotatable about spaced parallel axes, magnetic wire arranged for transfer between said spools, said wire winding in multiple layers thereupon whereby the efiective winding diameters and the relative speeds of the two spools changes in complementary fashion substantially continuously during transferal of the wire, a reversing drive, means for selectively actuating one of said spools thereby for reversibly advancing the wire, means for comparing the respective rotative speeds of sad two spools and indicating the ratio thereof, means for controlling said reversing drive including latch means for selectively setting and maintaining said drive in condition to operate in either direction, and means actuated by said comparison means for tripping said latch and rendering said drive inoperative responsive to a preselected value of said ratio.

HERMAN NYGAARD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,414,941 Gill May 2, 1922 1,850,102 Grout Mar. 22, 1932 2,457,699 Marsden Dec. 28, 1948 

